The present invention relates to a disposable diaper for absorption and containment of body wastes.
A disposable diaper disclosed in Japanese Unexamined Patent Application Publication No. 1999-342156 (hereinafter referred to as “Citation 1”) includes an upper sheet above a liquid-pervious topsheet. The upper sheet is bonded to the diaper along an outer peripheral portion of the upper sheet and a crotch region of the diaper is formed in its transversely middle zone with an opening which is, in turn, provided along its peripheral portion with an elastic member attached in stretched state thereto. The elastic member contracts and the peripheral portion of the opening is spaced apart from the topsheet as the diaper is curved in a back-and-forth direction. This known diaper allows body wastes to be caught in a space defined between the upper sheet and the topsheet by aligning the opening of the upper sheet with the wearer's anus and urinary organs. Such upper sheet serves as means adapted to prevent body wastes from coming in contact with the wearer's skin. Thin rubber threads or the like are used as the elastic member attached to the upper sheet.
A disposable diaper disclosed in Japanese Unexamined Patent Application Publication No. 1993-285174 (hereinafter referred to as “Citation 2”) includes an upper sheet a liquid-pervious first upper sheet and a liquid-resistant second upper sheet on the upper surface of the first upper sheet wherein the second upper sheet is formed in its middle zone with an opening extending in a back-and-forth direction of the diaper. Liquid-resistant flaps extending from transversely opposite side edges of the opening and these flaps are provided along respective outer side edge portions with elastic members. Longitudinally opposite end portions of each of the flaps are bonded to the second upper sheet. In this diaper also, the second upper sheet serves as a means adapted to prevent body wastes from coming in contact with the wearer's skin and thin rubber threads or the like are used as the elastic members attached to the second upper sheet.
Each of the diapers disclosed in Citations 1 and 2 includes the upper sheet provided above the topsheet covering the absorbent core and serving as a means to prevent body waste from coming in contact with the wearer's skin. In both cases, contraction of the elastic members attached to the upper sheet brings the upper sheet in close contact with the wearer's skin In these diapers, however, the elastic members comprising thin rubber threads may locally irritate the wearer's skin and cause pain and/or rash